Lattice　Boltzmann　method　(LBM)　is　employed　to　investigate　pore-scale　flow　and　mass　transport　in　a　carbon　paper　gas　diffusion　layer　(GDL)　of　interdigitated　PEMFC.　The　carbon　paper　GDL　is　reconstructed　using　the　stochastic　method,　and　its　macroscopic　transport　properties　are　numerically　predicted.　The　predicted　anisotropic　permeabilities　and　effective　diffusivity　of　the　reconstructed　GDL　agree　well　with　existing　measurements.　Then,　effects　of　the　porous　structures　of　the　carbon　paper　GDL　are　explored　in　terms　of　fluid　flow,　species　transport　and　electrochemical　reaction.　The　GDL　porous　structures　greatly　affect　flow　and　mass　transport,　creating　distinct　specie　concentration　distribution　and　local　current　density　distribution.　Besides,　simulations　are　performed　to　explore　liquid　water　behaviors　in　the　reconstructed　GDL　The　simulation　results　present　a　detailed　description　of　the　pore-scale　liquid　water　behaviors.　Further,　simulations　are　performed　to　investigate　the　effects　of　land　width　and　GDL　contact　angle　on　liquid　water　removal　time　and　residual　saturation.　Narrower　land　reduces　liquid　water　removal　time　and　residual　saturation.　Higher　contact　angle　increases　the　removal　time　and　reduces　the　residual　saturation.　Crown　Copyright　(C)　2011　Published　by　Elsevier　Masson　SAS.　All　rights　reserved.